Bastus Trump Orphion, £2.99

Compatibility: iPad (requires iOS 5.0 or later)

Orphion makes the most of the iPad’s multi-touch interface by enabling you to play both pitched and percussive sounds from the same pad-based interface. There are nine layouts, and the tones you create depend on where and how you touch each pad. Demo video here.

VirSyn iVoxel 2.0, £3.99

This classy iOS vocoder has received a significant update, with real-time pitch following, automatic tuning to a selectable scale, improved sound quality, a polyphonic sequencer and a redesigned interface among the new features. There’s support for Virtual MIDI, SoundCloud export and WIST, too.

Masao Suzaki Petites Ondes, £1.99

Compatibility: iPad (requires iOS 4.2 or later)

The Ondes Martenot was an early electronic instrument that was invented in 1928, and this iPad app is an emulation of it. It produces one tone at a time; your right hand is used to alter its pitch, while your left can control dynamics. Check out a demo video.

Periscope Audio Lab SpaceSampler, Free

Convolution technology comes to iOS with an app that enables you to record, apply filters (Impulse Responses), set the mix and then share the resulting sound. The IRs come from real gear and acoustic spaces, and you can export via email Audio Copy, Dropbox and SoundCloud.